Greencalculus is answering right now. Last checked 3 min ago. 45 installs a week from npm. It exposes 12 tools.
Sourced carbon emission factors + audit-traced calculations an AI can cite.
Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 16 August 2026. No other catalogue keeps this.
Today is the operative word: we check Greencalculus every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.
Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 3 min ago.
claude mcp add api --transport http https://mcp.greencalculus.com
{
"mcpServers": {
"api": {
"url": "https://mcp.greencalculus.com"
}
}
}
[mcp_servers.api]
url = "https://mcp.greencalculus.com"
{
"mcpServers": {
"api": {
"url": "https://mcp.greencalculus.com"
}
}
}
{
"mcpServers": {
"api": {
"url": "https://mcp.greencalculus.com"
}
}
}
This one needs environment variables set before it will start:
GREENCALCULUS_API_KEY (GreenCalculus API key — free at greencalculus.com/developers. Without one, search_factors and explain_absence still work; the other ten tools are refused.).
The author declared them in the registry entry; get the values from the project itself.
Read directly from the server with tools/list, grouped by what they act on.
If a tool disappears, we record the date.
calculate_activity
calculate_business_travel
calculate_electricity
calculate_embodied
calculate_freight
calculate_pcaf
calculate_spend
lookup_factor
lookup_factors
explain_absence
search_factors
resolve_factor
| URL | Transport | State | Latency | Checked |
|---|---|---|---|---|
| https://mcp.greencalculus.com | streamable-http | answering | 112 ms | 3 min ago |
Construction takeoff calculators (concrete, gravel, asphalt, roofing) and sourced constants.
Trace AI agent execution: every tool call, every error, every dollar. Open source, local-first.
UAE travel and living cost calculators with the published source behind every number.
Variable relationships from research papers with causal direction and source traceback.
Bulge-tier financial model factory — live formulas, source-traced cells, 14 templates.
Timestamped audit log for every AI conversation — stored locally in SQLite, owned by you.
Search DataCite datasets and software, fetch DOI metadata, trace relations, format citations.
Search scholarly sources, verify references, and export citations with traceable evidence.
Answers built from our own checks of this server.